It kind of depends if you've got access to solar... We have a 6kW solar system at home and for the most part we try and make it the only energy source charging our EV, mostly because i hate importing grid power when the EV is on charge. We usually look at the weather forecast each weekend and plug in when the sun is shining the most...and if we aren't bashing the solar on a washing day wih the dryer going

That worked well through Summer and into Autumn, but i do agree that in the last month, i've definitely done refills from grid as the sun is not out as much during winter. It will be interesting to review a years worth of charging and see how much grid we use, as we've only had the EV for about 6 months now.